Data Originator's Processing

Data were downloaded by the Proudman Oceanographic Laboratory (POL) (since 01 April 2010, the National Oceanography Centre Liverpool (NOCL)) from the instrument logger, and factory calibrations were applied to the temperature and conductivity channels. The instruments are returned to the manufacturer for recalibration approximately every two years. The data were then reformatted by POL/NOCL to a standard ASCII format.

Before the data were supplied to BODC, basic quality control was performed by the Data Originator. The first stage of quality checks involved comparing the data from each instrument with CTD measurements recorded during the deployment and recovery of the mooring. Following the comparison against CTD data secondary checks were performed by comparing the data from each instrument against the data from other sensors attached to that mooring. The Originator has provided BODC with a document containing a full description of the quality control methodology . Depending on the result of the quality checks for each series, one of the following actions was performed by the Originator:

The data was declared good quality and no corrections were applied.

Series with consistent offsets, spikes or periods of bad data were edited to correct for these issues. Spikes and periods of unrealistic values were converted to NaN values.

The series was marked as 'use with caution', if there were problems which the Originator was unable to correct, or it was unclear whether there was a problem with the data.

If the quality of the data from a series was extremely poor, then the Originator recommended that the data should not be used.

A full description of the results of these quality checks can be found in the relevant Originator's data processing comments document.

Sea-Bird SBE 16plus SEACAT

The SBE 16 plus is a high accuracy conductivity and temperature recorder (pressure optional). It is designed for moorings and other long-duration, fixed-site deployments. The SBE 16 plus has 6 amplified A/D input channels and conditioned power of 500 ma is avaliable for auxiliary sensors, dissolved oxygen, turbidity, fluorescence, PAR etc.

The SBE 16 plus is available with a choice of RS-232 or RS-485 interface.

The data were provided to BODC in ASCII format, and the series were reformatted into BODC standard internal format using a transfer function. The following table shows how the Originator's variables present in the Seapoint 16 plus data were mapped to the appropriate BODC parameter codes.

Originator's Variable

Units

Description

BODC Parameter Code

Units

Comments

Temperature

°C

Temperature of the water column

TEMPPR01

°C

-

Conductivity

S m -1

Electrical conductivity of the water column by in-situ conductivity cell

CNDCPR01

S m -1

-

Pressure

dbar

Pressure exerted by the water column

PREXPS01

dbar

-

Turbidity

FTU

Turbidity of the water column by Seapoint turbidity meter and laboratory calibration against formazin

TURBSP01

NTU

FTU=NTU

Salinity

None

Practical salinity of the water column by conductivity cell and computation using UNESCO 1983 algorithm

PSALPR01

None

-

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.

General Data Screening carried out by BODC

BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.

Header information is inspected for:

Irregularities such as unfeasible values

Inconsistencies between related information, for example:

Times for instrument deployment and for start/end of data series

Length of record and the number of data cycles/cycle interval

Parameters expected and the parameters actually present in the data cycles

Originator's comments on meter/mooring performance and data quality

Documents are written by BODC highlighting irregularities which cannot be resolved.

Data cycles are inspected using time or depth series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non-oceanographic origin may be tagged with the BODC flag denoting suspect value; the data values will not be altered.

The following types of irregularity, each relying on visual detection in the plot, are amongst those which may be flagged as suspect:

If a large percentage of the data is affected by irregularities then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.

Inconsistencies between the characteristics of the data set and those of its neighbours are sought and, where necessary, documented. This covers inconsistencies such as the following:

Maximum and minimum values of parameters (spikes excluded).

The occurrence of meteorological events.

This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

National Oceanography Centre, Southampton (NOCS)

Plymouth Marine Laboratory (PML)

Marine Biological Association (MBA)

Sir Alister Hardy Foundation for Marine Science (SAHFOS)

Proudman Oceanographic Laboratory (POL)

Scottish Association for Marine Science (SAMS)

Sea Mammal Research Unit (SMRU)

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

British Oceanographic Data Centre (BODC), hosted at POL

Permanent Service for Mean Sea Level (PSMSL), hosted at POL

Culture Collection of Algae and Protozoa (CCAP), hosted at SAMS

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

improve knowledge of how the seas behave, not just now but in the future;

help assess what that might mean for the Earth system and for society;

assist in developing sustainable solutions for the management of marine resources for future generations;

enhance the research capabilities and facilities available for UK marine science.

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

Climate, circulation and sea level (Theme 1)

Marine biogeochemical cycles (Theme 2)

Shelf and coastal processes (Theme 3)

Biodiversity and ecosystem functioning (Theme 4)

Continental margins and deep ocean (Theme 5)

Sustainable marine resources (Theme 6)

Technology development (Theme 8)

Next generation ocean prediction (Theme 9)

Integration of sustained observations in the marine environment (Theme 10)

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

physical, biological and chemical parameters sampling throughout the North and South Atlantic during collaborative research cruises aboard NERC's research vessels RRS Discovery, RRS James Cook and RRS James Clark Ross;

the Continuous Plankton Recorder being deployed by SAHFOS in the North Atlantic and North Pacific on 'ships of opportunity';

physical parameters measured and relayed in near real-time by fixed moorings and ARGO floats;

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.

Oceans 2025 Theme 10

Oceans 2025 is a strategic marine science programme, bringing marine researchers together to increase people's knowledge of the marine environment so that they are better able to protect it for future generations.

Theme 10: Integration of Sustained Observations in the Marine Environment spans all marine domains from the sea-shore to the global ocean, providing data and knowledge on a wide range of ecosystem properties and processes (from ocean circulation to biodiversity) that are critical to understanding Earth system behaviour and identifying change. They have been developed not merely to provide long-term data sets, but to capture extreme or episodic events, and play a key role in the initialisation and validation of models. Many of these SOs will be integrated into the newly developing UK Marine Monitoring Strategy - evolving from the Defra reports Safeguarding our Seas (2002) and Charting Progress (2005), thus contributing to the underpinning knowledge for national marine stewardship. They will also contribute to the UK GOOS Strategic Plan (IACMST, 2006) and the Global Marine Assessment.

Sustained, systematic observations of the ocean and continental shelf seas at appropriate time and space scales allied to numerical models are key to understanding and prediction. In shelf seas these observations address issues as fundamental as 'what is the capacity of shelf seas to absorb change?' encompassing the impacts of climate change, biological productivity and diversity, sustainable management, pollution and public health, safety at sea and extreme events. Advancing understanding of coastal processes to use and manage these resources better is challenging; important controlling processes occur over a broad range of spatial and temporal scales which cannot be simultaneously studied solely with satellite or ship-based platforms.

Considerable effort has been spent by the Proudman Oceangraphic Laboratory (POL) in the years 2001 - 2006 in setting up an integrated observational and now-cast modelling system in Liverpool Bay (see Figure), with the recent POL review stating the observatory was seen as a leader in its field and a unique 'selling' point of the laboratory. Cost benefit analysis (IACMST, 2004) shows that benefits really start to accrue after 10 years. In 2007 - 2012 exploitation of (i) the time series being acquired, (ii) the model-data synthesis and (iii) the increasingly available quantities of real-time data (e.g. river flows) can be carried out through Sustained Observation Activity (SO) 11, to provide an integrated assessment and short term forecasts of the coastal ocean state.

Overall Aims and Purpose of SO 11

To continue and enlarge the scope of the existing coastal observatory in Liverpool Bay to routinely monitor the northern Irish Sea

To develop the synthesis of measurements and models in the coastal ocean to optimize measurement arrays and forecast products. Driving forward shelf seas' operational oceanography with the direct objective of improving the national forecasting capability, expressed through links to the National Centre for Ocean Forecasting (NCOF)

To exploit the long time-series of observations and model outputs to: a) identify the roles of climate and anthropogenic inputs on the coastal ocean's physical and biological functioning (including impacts of nutrient discharges, offshore renewable energy installations and fishing activity) taking into consideration the importance of events versus mean storms / waves, river discharge / variable salinity stratification / horizontal gradients; b) predict the impacts of climate change scenarios; and c) provide new insights to Irish Sea dynamics for variables either with seasonal cycles and interannual variability, or which show weak or no seasonal cycles

To provide and maintain a 'laboratory' within which a variety of observational and model experiments can be undertaken (Oceans 2025 Themes 3, 6, 8, 9), including capture of extreme events

Demonstrate the value of an integrated approach in assessment and forecasting

Demonstrate the coastal observatory as a tool for marine management strategies through collaboration with the Environment Agency (EA), Department for Environment, Food and Rural Affairs (DEFRA), Joint Nature Conservation Commmittee (JNCC), English Nature (EN), Department of Agriculture and Rural Development (DARD), and Local Authorities, providing management information pertinent to policy (e.g. Water Framework Directive)

Proudman Oceanographic Laboratory Rig#1030

Deployment and Recovery

This rig was deployed as part of the Liverpool Bay Coastal Observatory during R.V. Prince Madog cruise PD07_08. All of the major mooring objectives were accomplished. However, CTD sites were missed out and both 24 hour stations aborted, due to very poor weather conditioned throughout the cruise. Work was essentially carried out during lulls between 2-3 storms during the week commencing 10 March 2008. Recovery of the rig took place during R.V. Prince Madog cruise PD09_08.

Rig Position

53° 26.970'N 3° 38.526'W

Water Depth

25.3 m

Deployed

14 March 2008 18:30 GMT

Recovered

16 April 2008 15:48 GMT

No. of days

33

Rig Description

This rig is a bottom frame comprising of the following instruments 0.5 m above the seabed; Wave Acoustic Doppler Current Profiler (ADCP); Telemetry ADCP; and a SeaBird 16plus. The frame was fitted with two Benthos releases s/n 71922 - Rx 11.5 kHz, Tx 12.0 kHz release A, and s/n 67879 - Rx 11.5 kHz, Tx 12.0 kHz release B, both with a fizz link, and a spooler with 200 m of rope for recovery of the ballast weight.

Fitted to base of frame with pumped conductivity sensor underneath.SeaPoint turbidity sensor 10320 taped to roll bar; set up for 0 - 125 FTU range.Clock set at 15:35:00 on 10 March 2008; delayed start at 06:00:00 on 11 March 2008.

Sound velocity calculated from temperature, depth and salinity of 32.Clock reset at 16:41:00 on 10 March; delayed start at 06:00:00 on 13 March 2008.LinkQuest acoustic modem set for transmission of ADCP data every hour.

Fixed Station Information

Station Name

Coastal Observatory Site 21

Category

Offshore location

Latitude

53° 27.13' N

Longitude

3° 38.48' W

Water depth below MSL

25.0 m

Liverpool Bay Coastal Observatory Site 21

This station is one of 34 stations regularly visited by the Proudman Oceanographic Laboratory (POL) as part of the Liverpool Bay Coastal Observatory. The main activity at this site are CTD profiles (since August 2002) which are taken during each site visit. This station was also the secondary mooring site (also referred to as Site B) for the Coastal Observatory project between April 2005 and March 2010. After March 2010 the moorings were moved to site 20. The station lies within a box of mean water depth 24 m with the following co-ordinates:

Box Corner

Latitude (+ve North)

Longitude (+ve East)

North-west corner

53.46028

-3.658

South-east corner

53.44249

-3.6105

The position of this station relative to the other POL Coastal Observatory sites can be seen from the figure below.